package com.yixin.ystartlibrary.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * User: YStar
 * Date: 2018/1/28
 * Content AES加密解密类:
 */

public class AESEncryptUtil {
	// 算法/模式/填充
	private static final String CIPHER_MODE = "AES/CBC/PKCS5Padding";
	private static final byte[] IV = { 0x12, 0x14, 0x16, 0x18, 0x20, 0x22,
			0x24, 0x26, 0x28, 0x30, 0x32, 0x34, 0x36, 0x38, 0x40, 0x42 };
	// 密匙goldeneye_2014062312_key（32位MD5转换）01469DA0D9F57154E81EE073D931FAA7
	private static final String ENCRYPT_KEY = "holuisoft_201510";

	/**
	 * 创建密钥
	 * 
	 * @param password
	 *            128位 16*8 所有密钥长度不能超过16字符中文占两个
	 */
	private static SecretKeySpec createKey(String password) {
		byte[] data = null;
		if (password == null) {
			password = "";
		}
		StringBuffer sb = new StringBuffer(16);
		sb.append(password);
		while (sb.length() < 16) {
			sb.append("0");
		}
		if (sb.length() > 16) {
			sb.setLength(16);
		}
		try {
			data = sb.toString().getBytes("UTF-8");
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return new SecretKeySpec(data, "AES");
	}

	// 加密字节数据
	private static byte[] encrypt(byte[] content) {
		try {
			SecretKeySpec key = createKey(ENCRYPT_KEY);
			Cipher cipher = Cipher.getInstance(CIPHER_MODE);
			IvParameterSpec zeroIv = new IvParameterSpec(IV);
			cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv);
			byte[] result = cipher.doFinal(content);
			return result;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 加密(结果为16进制字符串)
	 * 
	 * @param content
	 *            要加密的字符串
	 * @return 加密后的16进制字符串
	 */
	public static String encrypt(String content) {
		if (content == null)
			return null;
		byte[] data = null;
		try {
			data = content.getBytes("UTF-8");
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}

		data = encrypt(data);
		String result = Base64.encode(data);
		return result;
	}

	// 解密字节数组
	private static byte[] decrypt(byte[] content) {
		try {
			SecretKeySpec key = createKey(ENCRYPT_KEY);
			Cipher cipher = Cipher.getInstance(CIPHER_MODE);
			IvParameterSpec zeroIv = new IvParameterSpec(IV);
			cipher.init(Cipher.DECRYPT_MODE, key, zeroIv);
			byte[] result = cipher.doFinal(content);
			return result;
		} catch (Exception e) {
//			e.printStackTrace();
		}
		return null;
	}

	/** 解密16进制的字符串为字符串 **/
	public static String decrypt(String content) {
		if (content == null)
			return null;
		byte[] data = null;
		try {
			data = Base64.decode(content);
		} catch (Exception e) {
			e.printStackTrace();
		}
		data = decrypt(data);
		if (data == null)
			return null;
		String result = null;
		try {
			result = new String(data, "UTF-8");
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return result;
	}

	public static class Base64 {
		private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
				.toCharArray();

		/**
		 * data[]进行编码
		 * 
		 * @param data
		 * @return
		 */
		public static String encode(byte[] data) {
			int start = 0;
			int len = data.length;
			StringBuffer buf = new StringBuffer(data.length * 3 / 2);

			int end = len - 3;
			int i = start;
			int n = 0;

			while (i <= end) {
				int d = ((((int) data[i]) & 0x0ff) << 16)
						| ((((int) data[i + 1]) & 0x0ff) << 8)
						| (((int) data[i + 2]) & 0x0ff);

				buf.append(legalChars[(d >> 18) & 63]);
				buf.append(legalChars[(d >> 12) & 63]);
				buf.append(legalChars[(d >> 6) & 63]);
				buf.append(legalChars[d & 63]);

				i += 3;

				if (n++ >= 14) {
					n = 0;
					buf.append(" ");
				}
			}

			if (i == start + len - 2) {
				int d = ((((int) data[i]) & 0x0ff) << 16)
						| ((((int) data[i + 1]) & 255) << 8);

				buf.append(legalChars[(d >> 18) & 63]);
				buf.append(legalChars[(d >> 12) & 63]);
				buf.append(legalChars[(d >> 6) & 63]);
				buf.append("=");
			} else if (i == start + len - 1) {
				int d = (((int) data[i]) & 0x0ff) << 16;

				buf.append(legalChars[(d >> 18) & 63]);
				buf.append(legalChars[(d >> 12) & 63]);
				buf.append("==");
			}

			return buf.toString();
		}

		private static int decode(char c) {
			if (c >= 'A' && c <= 'Z')
				return ((int) c) - 65;
			else if (c >= 'a' && c <= 'z')
				return ((int) c) - 97 + 26;
			else if (c >= '0' && c <= '9')
				return ((int) c) - 48 + 26 + 26;
			else
				switch (c) {
				case '+':
					return 62;
				case '/':
					return 63;
				case '=':
					return 0;
				default:
					throw new RuntimeException("unexpected code: " + c);
				}
		}

		/**
		 * Decodes the given Base64 encoded String to a new byte array. The byte
		 * array holding the decoded data is returned.
		 */

		public static byte[] decode(String s) {

			ByteArrayOutputStream bos = new ByteArrayOutputStream();
			try {
				decode(s, bos);
			} catch (IOException e) {
				throw new RuntimeException();
			}
			byte[] decodedBytes = bos.toByteArray();
			try {
				bos.close();
				bos = null;
			} catch (IOException ex) {
				System.err.println("Error while decoding BASE64: "
						+ ex.toString());
			}
			return decodedBytes;
		}

		private static void decode(String s, OutputStream os)
				throws IOException {
			int i = 0;

			int len = s.length();

			while (true) {
				while (i < len && s.charAt(i) <= ' ')
					i++;

				if (i == len)
					break;

				int tri = (decode(s.charAt(i)) << 18)
						+ (decode(s.charAt(i + 1)) << 12)
						+ (decode(s.charAt(i + 2)) << 6)
						+ (decode(s.charAt(i + 3)));

				os.write((tri >> 16) & 255);
				if (s.charAt(i + 2) == '=')
					break;
				os.write((tri >> 8) & 255);
				if (s.charAt(i + 3) == '=')
					break;
				os.write(tri & 255);

				i += 4;
			}
		}

	}

}